Vocalisations

Calls probably representing advertisement calls were recorded in February 2015 from two adult males (SVL 114 and 121 mm) kept in a terrarium (L × W × H = 71 × 50.5 × 40 cm; filled with water (7 cm depth), with some reed and grass material) overnight together with two females (SVL 103 and 128 mm). Calls were recorded above water with the built-in microphone of a waterproof camera (Pentax; WG-II) and an acoustic recorder (SM2+; Wildlife Acoustics Inc.) that also recorded air temperature. Water temperature was measured by a Thermochron iButton datalogger. Recordings were analysed at a sampling rate of 44.1 kHz and 16-bit resolution with Cool Edit Pro 2.0. We measured interval length between calls and six acoustic features for each call, including call duration, expiratory note duration, inspiratory note duration, dominant frequency of the total call, and of presumed expiratory and inspiratory notes (Glaw and Vences, 1991). Vocalisations were illustrated using the R package ‘seewave’ (Sueur et al., 2008). Call recordings were submitted to the FonoZoo sound archive (http://www.fonozoo.org); accession numbers 9850–9854.